(16). Prefer iPhone over Android if possible. (Do not debate here on my thread about this. First do own research. I am saying this after lots of research and experience).
(17). On Iphone keep backround usages of apps off and do not give access to your contact msg and notification access to every app.
(18). Hacking an iPhone remotely is very hard (Not impossible) but most of the iphone hack is done by physical contact (possible In 10-30sec), So be careful with whom you sharing your mobile.